Study On Quality Evaluation Of Dried Litchi

China is the world’s largest litchi cultivation country and is the largest litchi production country also. At the present, fresh market litchi in China is less than10%of production, the rest of the litchi must be processed. Dried litchi fruit account for more than80%of all processed litchi fruit. As dried litchi varieties are more varied, resulting in relatively poor quality of dried litchi fruit product, and the competition in the international market at a disadvantage. China annual needs for quality dried litchi fruit must be imported from Vietnam and other countries. Therefore, to evaluate the processing quality of dried litchi, to pick out the suitable dried litchi varieties, to improve the quality of dried litchi fruit, and to increase its competitiveness in the international market have far-reaching significance.The study selected a number of evaluating indicators applied to the evaluation of processing quality of dried litchi. Through the classification by principal component, sensory evaluation, and sensory evaluation indicators, a number of good quality dried litchi samples were selected. Regression equation was established based on excellent sample of dried litchi and previously established discriminant dried litchi fruit processing quality pros and cons mathematical evaluation method. Select fresh fruit with good quality and then dry the fruit and use them to study the effects of temperature and light on processed quality during storage to determine the optimal storage conditions.The main results and conclusions of this study are as follows:1.In this study, by using SPSS16.0software analysis, it was found that among11indicators to evaluate the quality of dried litchi fruit, edible rate and stone size, protein content and sugar acid ratio, sugar acid ratio and total acid content showed a certain degree of negative correlation. The juice outflow rate and the rate of broken shell, edible rate and skin a*, dried fruit weight and stone size, protein content and total acid content,sugar-acid ratio and total sugar content showed some positive correlation; Among other indicators, although related, but not significant.2.Principal component corresponding eigenvalue accounted for a proportion of the total extracts eigenvalues based on principal component analysis, and the degree of sensory evaluation reflected in the corresponding principal component, giving sensory evaluation of taste, peel color, flesh color and shapes of fruits35.8%,30.7%,16.75%and16.75%, respectively, of the weight.3.According to sensory indicators weight, given by the scoring, ultimately selected24good quality dried litchi samples, as follows:’Nuomichi’(Linshan)、’Nanshepi’(Guangdong)、 Jizui’(Linshan)、’Nuomici’(zengcheng)、’Zhoushaqiu’(Guangdong)、’Jiju’(Hefu)、’Xiangjinfeng’(Guangdong)、’Baitangyin’(Linshan)、’Shuangjianyuhebao’(Zhangpu)、’Guiwei’(Zhangpu)、’Yamulong (Hainan)、Tianyan’(Guangdong)、’Jizui’(Maomin)、’Feizixiao’(Zhangpu)、’Mili’(Linshan)、’Guiwei’(Conghua)、’Nuomici’(Conghua)、’Bainuomici’(Shantou)、’Shuidong’(Guangdong)、’Xijiaozi’(Guangdong)、’Jiaohe’(Linshan)、’Yongliu’(Hainan)、’Hongxiuqiu’(Guangdong)and’Mitangchen’(Zengchen).4.Obtained by principal component analysis, principal component composite score showed:’Mili’(Linshan)、’Jizui’(Linshan) and’Yamulong’(Hainan) were three of the best-quality dried litchi samples、’Xiafangzhi’(Zhangzhou)、’Laopinzhong’(Yunnan)、’Baina’(Yunnan) and ’Dasigou’(Shantou) were four worst-dried litchi samples5.According to the the validation regression equation and its excellent differential corresponding to the range, the eventual establishment of litchi fruit dried processing quality evaluation mathematical equation and its value ranges are as follows: Fe=0.011*X1+0.056*X2+0.123*X3+0.045*X4+0.033*X5+0.076*X6+0.075*X7-0.202*X8+0.238*X9+0.061*X10+0.215*X11F≥0.467was suitable;-0.426≤F<0.467was more appropriate; F<-0.426was inappropriate.6.0℃can effectively control litchi dried fruit pericarp browning during storage, inhibitthe decline of fructose, glucose, sucrose, total sugar content, the sugar acid ratio, and can inhibit acid content increased late in storage, so dried litchi fruit should be stored under0℃conditions.Dark treatment could effectively control the brightness of dried litchi peel, red hue, inhibitof the decrease of glucose, fructose, sucrose and total sugar content. Although the acid content of dried litchi in dark treatment during late storage rose faster than other treatments, the sugar-acid ratio was not reduced, and did not affect the taste and quality. Taken together, dried litchi fruit should be stored in a dark environment.